Transcutaneous electrical nerve stimulation (TENS) is the use of a high frequency electrical stimulation which is applied to an area of the body to relieve pain. In the case of an incision, an electrode is applied to each side of the incision so that small electrical impulses stimulate the nerve area. In many cases, this stimulation greatly reduces or eliminates the pain sensation. The advantage of TENS is that it is a non-invasive and non-narcotic method of managing pain. TENS does not cure or eliminate the cause of the pain, rather it diminishes the feeling of the pain. Thus, with the use of TENS, patients are often able to cough or ambulate more comfortably in situations where normal pain would have precluded this. And because the pain is substantially reduced, narcotic drugs can often be eliminated so that the patient is not drowsy and does not experience the ups and downs of narcotic usage.
There are numerous electrodes in the prior art, some of which have been used for TENS. For instance, in U.S. Pat. No. 3,817,252 to Maurer, an electrode designed for TENS is disclosed which has both a low impedance screen and a diffuser screen beneath a pad. Another body surface electrode, disclosed in U.S. Pat. No. 3,607,788 to Adolph and Bernstein, consists of a liquid electrode which dries on the skin. An electrode consisting of a metal foil body has also been disclosed in U.S. Pat. No. 3,817,253 to Gonser.
A difficulty which has been experienced with prior art electrodes is their lack of stretchability. Often, when a patient moves, the skin to which the electrode is attached stretches. In many cases, this skin stretching either causes the electrode to come loose as the adhesive holding the electrode to the skin breaks away from the skin, or the electrode to break in two. Another difficulty with prior art devices is that they have not been sufficiently flexible. As a result of this, when the patient's body flexes, the electrode has pressure points which create higher current densities in spots. This lack of flexibility also increases the likelihood that the adhesive holding the electrode to the body will break away.